轻质开孔泡沫金属超声波焊多孔接头的性能调控机制和连接机理研究

The high-porosity open-cell metal foam with the three-dimensional skeleton structure has broad application prospects in the field of high-capacity battery production. However, the existing joining technology of foam metal cannot meet the needs of high-porosity open-cell metal foam, and the joints of metal foam also cannot be effectively characterized due to the lack of basic theoretical. This has become a great technical bottleneck restricting the development of battery manufacturing..In this project, the ultrasonic welding technology coupled with precision control, which is a new solid-state welding method with the excellent characteristic of high welding efficiency and low heat input, is proposed to achieve the reliable joining of open-cell metal foam. The characteristics of open-cell metal foam will be preserved to the greatest extent after welding. The evaluation system for the ultrasonic welded porous joints will be established to optimize the key parameters in the welding process. Based on the analysis results of joint interface and the evolution rules using multi-scale modeling, the connection mechanism of ultrasonic welded porous joints for open-cell metal foam will be discussed, and the regulation mechanism of microstructure and performance of ultrasonic welding process for high-porosity open-cell metal foam will be established. The obtained results of this project would not only provide technical support for expanding the application of high porosity open-cell metal foam but also leading a new development direction for lightweight manufacturing in the battery manufacturing field. Thus, this project has both great scientific research value and economic benefits.

具有三维骨架结构的高孔隙率开孔泡沫金属在高容量电池生产领域具有广阔的应用前景。但是现有的泡沫金属连接技术难以满足高孔隙率开孔泡沫金属实际连接的需要，基础理论研究和有关数据的缺乏导致泡沫金属接头不能得到有效表征，已经成为了限制电池制造发展的技术瓶颈之一。. 本项目提出采用精密控制超声波焊接技术实现开孔泡沫金属的多孔化可靠焊接，借助其焊接效率高和低热输入等优势，在最大程度上保存开孔泡沫金属的结构和特性。建立高孔隙率开孔泡沫金属超声波焊多孔接头的评价体系，遴选焊接过程中的关键参数并进行优化。基于接头界面演化规律和多尺度建模探讨开孔泡沫金属超声波焊多孔接头的连接机制，建立开孔泡沫金属超声波焊接过程组织和性能调控机制。本项目研究成果不仅可以为扩展高孔隙率开孔泡沫金属在电池制造领域的应用提供技术支撑，还可为电池制造领域轻量化生产带来全新发展方向，具有巨大的科学研究价值及经济效益。

泡沫金属在高容量电池的薄片状电极生产中具有广泛的应用前景，但是目前还缺乏高质、高效的泡沫金属连接工艺和泡沫金属焊接接头质量评价体系，这在一定程度上限制了泡沫金属在电池制造领域的进一步应用。本项目提出一种高质、高效的高孔隙率开孔泡沫铜/实体铝板异种金属超声波焊多孔接头制备方法，基于关键部件的设计制造完成了适用于高孔隙率开孔泡沫金属焊接的超声波焊接系统搭建。探讨焊头端面花纹和关键焊接参数对接头质量的影响和交互作用，最优工艺参数下获得的接头拉伸载荷与开孔泡沫铜母材相当，实现高孔隙率开孔泡沫铜/实体铝板异种金属的高效可靠连接的同时尽量减少对高孔隙率开孔泡沫金属多孔结构的破坏。建立的超声波焊接质量实时监测平台和多孔接头焊后评价体系可以较好地反映多孔接头的摩擦、塑变、界面流动和骨架变形，充分满足高孔隙率开孔泡沫金属超声波焊多孔接头的表征需求。.系统探讨了关键焊接参数对接头形貌、连接质量和界面特征的影响规律，对开孔泡沫铜侧的孔隙形貌、分布及连通性、骨架结构的变形压缩和连接界面质量评估进行了细观尺度的表征分析。高孔隙率开孔泡沫铜/实体铝板异种金属超声波焊接头的连接机制主要为原子扩散产生的冶金结合与材料流动产生的机械锁合。建立的多尺度仿真模型从不同尺度分析了开孔泡沫铜/实体铝板异种金属超声波焊接过程中的宏观热力演化规律、细观骨架和孔洞变形、微观扩散行为，有助于焊接工艺优化和连接机理探讨。高孔隙率开孔泡沫铜内部复杂且随机的骨架结构与焊头端面的四棱锥尖齿设计共同造成了局部的应力应变集中，对界面处材料的塑变、流动和扩散起到了重要作用。.项目的研究成果解决了高孔隙率开孔泡沫金属焊接面临的缺乏高效稳定焊接工艺、骨架结构大量熔化、接头成为性能薄弱点、接头不能得到有效表征等关键问题，对于促进泡沫金属在工业领域的推广和应用具有重要的理论意义和实际应用价值。